The present invention relates to a power operated surfboard and particularly to such a surfboard which may be used in a manner similar to a typical surfboard but with the advantage of having continuous power operation of the surfboard. In designing a powered surfboard, there are certain problems peculiar to a surfboard which are not present in connection with other watercraft construction. For one thing, the surfboard must be basically flat over the major portion of the upper surface to enable an operator to either stand or sit on the surfboard. The engine compartment must accordingly be relatively small and compact and at a position where it interferes as little as possible with the relatively flat upper surface desired for such a surfboard. Furthermore, it is imperative that the surfboard be as free of engine vibration as possible so as to enable the operator to manipulate the surfboard readily. In addition, it is highly desirable that the surfboard be relatively quiet since the operator is standing upon the surfboard and will be more disturbed by noise than an occupant of a boat. Moreover, it is highly desirable that water be kept out of the exhaust system of the engine as much as possible.
Motorized surfboards have previously been proposed. One such motorized surfboard is that shown in the Carter U.S. Pat. No. 3,324,822. This patent has the advantage that it provides for jet propulsion, thereby eliminating the need for a propeller which might cause injury to the operator or to someone in the water. The Carter patent, however, has a number of disadvantages including the fact that the drive shaft between the engine and the impeller is relatively long and horizontally disposed. This tends to make the surfboard relatively bulky in cross section throughout much of its length. Furthermore, the presence of such a long drive shaft will increase the tendency to vibration.
The Dawson U.S. Pat. No. 3,463,116 overcomes the disadvantage of a long drive shaft by placing the impeller and the engine both at the rear of the surfboard. While the Dawson arrangement was a marked advance over some of the prior surfboards, it has certain disadvantages. In the first place, the engine rests upon an auxiliary molded floor located above the floor of the surfboard and the impeller is located beneath this floor. In addition, there is no effective means in the Dawson arrangement to prevent the entrance of water into the exhaust system while the board is standing still. Furthermore, Dawson shows no particular means for ensuring a relatively quiet operation of the surfboard. It is very important with such a power operated surfboard to minimize the noise as much as possible.